Method and apparatus for improving musical ability

ABSTRACT

A pair of recordings are synchronously reproduced, wherein one such recording suitably comprises a musical selection with which a student may correlate a response, while the second recording represents an ideal or correct response. The student hears the first recording continuously, but the second recording becomes audible to him only at the instance of his response coinciding with the information on the second recording. The student is thus given an immediate indication of the correctness of his response for the purpose of reinforcing the student&#39;&#39;s performance. Also, an overall indication or summary is provided of the student&#39;&#39;s ability.

United States Patent 1 [111 3,808,936 Shrader May 7, 1974 METHOD AND APPARATUS FOR 3,456,546 7/1969 Welsh et al. 84/478 IMPROVING MUSICAL ABILITY [76] Inventor: David L. Shrader, 11810 NE. 141st Primary Examiner lawre.nce Franklin st Kirkland wash. 98033 Attorney, Agent, or Flrfit-Klfll'QUlSt, Sparkman,

Campbell, Leigh, Hall & Whmston [22] Filed: Oct. 3, 1972 [21] Appl. No.: 294,525 [57] ABSTRACT 7 Related s Application Data A pair of recordings are synchronously reproduced, 63] Co tinuation of Ser No 53 081 Jul 8 1970 wherein one such recording suitably comprises a musiabglndoned y cal selection with which a student may correlate a response, while the second recording represents an ideal 52 us. Cl. .84/471 correct response The student hears the first [5]] 1m. can, 15/02 cording continuously, but the recording [58] Field of Search 84/454 470 471 477 comes audible to him Only the instance of his 8 1 3 sponse coinciding with the information on the second recording. The student is thus given an immediate in- 56] References Cited dication of the correctness of his response for the purpose of reinforcing the students performance. Also, 2 34 222 STATES PATENTS 3 I an overall indication or summary is provided of the l, 1 Lancaster 5 14 d 1" 7 2,416,353 2/l947 Shipman et al...... 84/470 X 8 en S a My 2,958,250 H/I96O Poehler 84/454 9 Claims, 6 Drawing Figures I01 l2 I4 24 7 MUSIC TA PE i- DECK AMPLIFIER HEADSET CHTB RHYTHM I COUNTER PATENIEB 7W 3808,9136

SHEET 1 OF 3 FIG. 1 :o 27 I4 24 TAPE usnc DECK RHYTHM AMPLIFIER HEADSET CPL-B.

COUNTER FIG. 2

CHANNEL A k CHANNEL B Ms k l l P *l FIG. 3 CHANNEL A k N CHANNEL B DAVID L. SHRADER INVENTOR BUCKHORN, BLORE, KLARQUIST & SPARKMAN ATTORNEYS PATENTED IIIIY 7 I974 SHEET 2 [IF 3 FIG. 4 O

TAPE 44 DECK SWITCHING 7 AMP. CONTROL HEADSET CONTROL TAPE DECK

COUNTER MUSIC TAPE CH.A AMP. HEADSET DECK REF. CH. B. PITCH AMP. AMP. MICROPHONE MODULATOR DETECTOR INDICATOR BUCKHORN, BLORE, KLARQUIST & SPARKMAN ATTORNEYS PATENTEDHAY H914 3808.936

SHEET 3 BF 3 DAVID L. 'SHRADER INVENTOR BUCKHORN, BLORE, KLARQUIST & SPARKMAN ATTORNEYS METHOD AND APPARATUS FOR IMPROVING MUSICAL ABILITY This is a continuation of application Ser. No. 53,081, filed July 8, 1970, now abandoned.

BACKGROUND OF THE INVENTION Evaluation of musical performance and ability, e.g. in the area of rhythm and pitch, has heretofore been largely subjective. Even with the ideal one-to-one teacher-pupilratio, the emphasis is still upon teacher interpretation, and the ability of the teacher to convey the proper corrective suggestion to the student. Despite the recognition that greater learning takes place with immediate reinforcement or rejection of student action, the complication and variations involved in music render the students specific actions difficult to isolate. Often, only an overall impression can be gained of the relative ability or inability of a particular student, and evaulation of performance is most often delayed.

SUMMARY OF THE INVENTION According to the present invention, first and second audio signals are simultaneously provided, for example from a pair of tracks on a single recording tape. The first audio signal comprises a sound sequence, such as a musical selection or the like, with which the student can correlate a response. For example, it may be desired the student respond rhythmically to the beat or tempo of the music, and the student may also be provided with sheet music for sight reading.

According to the present invention, a substantially immediate indication is given of the students correct response. For example, in case a rhythmic response is called for, the student will hear the second audio signal, comprising a correctly sychronized rhythmic beat, only insofar as his response coincides therewith. The students correct performance is thus reinforced. Also, a summary or score of the students overall performance is suitably provided.

As a result of the immediate reinforcement of the students correct action, the learning process is accelerated as compared with a subjective evaluation after the students performance. The student also enjoys the illusion of playing with the music or sound sequence which comprises the first audio signal.

It is accordingly an object of the present invention to provide an improved method and apparatus for ascertaining and improving a students musical ability.

It is another object of the present invention to provide improved method and apparatus for improving a students musical ability by immediate reinforcement of correct action.

It is a further object of the present invention to provide an improved method and apparatus for ascertaining and improving a students rhythmic ability.

It is another object of the present invention to provide an improved method and apparatus for improving a students pitch.

It is a further object of the present invention to provide an improved learning method and apparatus which provides the illusion of playing an instrument.

The subject matter which I regard as my invention is particularly pointed out and distinctly claimed in the concluding portion of this specification. The invention, however, both as to organization and method of operation, together with further advantages and objects DRAWINGS FIG. 1 is a block diagram of a first apparatus according to the present invention for ascertaining and improving rhythmic ability,

FIG. 2 is a representation of magnetic tape employed with the FIG. 1 apparatus, illustrating incorrect student response relative thereto,

FIG. 3 is another representation of the same recording tape, this time illustrating a correct student response,

FIG. 4 is a block diagram of an apparatus according to the present invention for switching taped programs according to the rhythmic ability of a particular student,

FIG. 5 is a block diagram of apparatus according to the present invention for ascertaining and improving a students pitch, and

FIG. 6 is a schematic diagram further illustrating exemplary circuitry employed in the apparatus shown in block diagram form in FIG. 1.

DETAILED DESCRIPTION Referring to the drawings and particularly to FIG. 1, the apparatus therein illustrated is employed for evaluating and improving the rhythmic ability of a student;

Tape deck 10 is a conventional magnetic tape recording and reproducing apparatus having the facility of simultaneously reproducing plural channels of recorded magnetic tape. For example, tape deck 10 may comprise a stereo tape player, wherein the two channels are designated channel A and channel B respectively. Channel A is suitably recorded with a substantially continuous sound, or series of sounds, constituting an audio sound sequence. The usual and possibly most satisfactory recording will be that of a musical selection having a discernible beat or tempo. However, some other natural or artificial sound sequence may be substituted therefor, such as the ticking of a metronome at a predetermined rate.

Channel B, on the other hand, is recorded to reproduce the correct beat or tempo audio signal which would normally also be associated with channel A, and which should be recognized by the student. That is, the channel B audio signal is correlated with the first sound sequence in the same manner as a students correct rhythmic response to the channel A sound sequence. In a particular instance, the channel B or rhythm channel comprised a recording of a small muted membraneaphone or bongo drum played in correct time with the channel A music.

Channel A and B audio signals from tape deck 10 are both coupled to a stereo amplifier 12 which produces separate amplified outputs l4 and 16 corresponding to the music and rhythm respectively. The music signal is substantially continuously coupled to headset 24 via series connected resistor 18 and variable resistor 20 in control unit 22. The rhythm signal is selectively coupled via control unit 22 to headset 24, with this signal being provided through relay contacts 26 and resistors 28 and 30, connected in series, to the junction of the aforementioned resistors 18 and 20. However, contacts 26 are normally open, inasmuch as relay coil 32 is normally not energized, and therefore the rhythm channel will normally not be heard in the headset.

Control unit 22 also includes a double throw push button 34 which is mechanically biased in a conventional manner for normally closing the right hand contacts thereof. These contacts couple a battery 36 in' charging relation to capacitor 38. The student can momentarily depress push button 34, closing the left hand contacts, and when the student does so, capacitor 38, theretofore charged by battery 36, will discharge through relay coil 32 and cause momentary closing of relay contacts 26. The circuit comprising the relay coil, the capacitor, and the battery constitute a timing circuit by means of which the rhythm channel, i.e. channel B is temporarily coupled to headset 24 for a predetermined short period of time. The discharge time constant of the capacitor 38, relay coil 32 circuit is suitably such that relay contacts 26 are held closed for approximately one tenth of a second, each time push button 34 is depressed. The student will therefore hear whatever is recorded on channel B only for such short period of time and must release the push button for recharging capacitor 38 before another segment of channel B can be heard by him.

A counter 40, comprising a conventional electromechanical counter, receives its input at the junction between resistors 28 and 30. The counter 40 is threshold operated such that if a rhythm signal is present when contacts 26 are closed, electronic circuitry in the counter 40 will amplify such information and increase the total registered count by one.

The operation achieved according to the present invention can be illustrated by visually depicting the placement of the magnetic signals on a magnetic stereo,tape. Referring to FIGS/2 and 3, channel A again represents a sound sequence or music channel, while channel B indicates the rhythm channel. Channel A" is suitably continuously recorded and is continuously heard by the student via the aforementioned headset 24 worn by the student. However, Channel B" may or may not be heard. Channel B is prerecorded with magnetic signals, MS, e.g. recording a membraneaphone beat, wherein each signal is correlated'with the natural beat of the recorded music, with each signal suitably having a duration of somewhat less than one tenth of a second. Period SR depicts the students response, or the period of time relay contacts 26 are closed after button 34 is depressed. The student attempts to operate the push button in time with the music he hears, and sometimes additionally in accordance with sheet music provided. In the instance illustrated in FIG. 2, the students response does not coincide with a prerecorded magnetic signal, and hence signal MS would not be heard by the student in headset 24.

In FIG. 3, on the other hand, the student has matched his response, SR, with the magnetic signal MS, indicative of correct timing. Therefore, the student will hear the signal MS in his headset.

Of course, if the student almost but not quite matches the desired signal, MS, only a part of the recorded signal will be heard. In a given instance, the gate" period constituting the period SR during which the student may hear channel B, can be made quite short and the signal MS can be made quite short in order to lessen the chance of overlap. In any case, the student can detect the difference between a correctly timed response and one that is not.

The student quickly receives reinforcement of correct rhythmic response with the method carried out by the apparatus FIG. 1, and can rapidly adjust his response so that he hears a greater proportion of the recorded rhythmic signals. Also, the student gains the illusion of playing the programed rhythm, accompa nying the music on channel A as his response is correct. Learning can rapidly take place with this system.

Other modes of operation for the FIG. 1 apparatus are possible. For example, the FIG. 1 apparatus may be operated in a reverse mode wherein the rhythmic signal is heard continuously except when a correct response is given by the student. A circuit including means for accomplishing the reverse mode is described below. However, this type of reinforcement has not been found as satisfactory in practice as the first mode described above.

Counter 40 registers the number of rhythmic beats which the student successfully identifies by means of push button 34. With successive runs of the same tape or different tapes, the student and his instructor can identify the students learning progress. The rating obtained thereby is entirely objective and provides a clear cut index of the particular students rhythmic and/or sight reading ability.

FIG. 4 illustrates an apparatus wherein the student, by his ability, can branch-program the apparatus to a different or more complex test of rhythm. In the FIG. 4 diagram, similar elements are referred by means of similar reference numerals. In addition, the apparatus is provided with a second tape deck, 11, which is connected to dual channel amplifier 12' substantially in parallel with the, output from tape deck 10. However, tape decks l0 and 11 are controlled by a switching control 42 whereby only one of the tape decks is operated at a particular time. Theinput 44 to switching control 42 is compared with a threshold in switching control 42 whereby, if the output of counter 40 exceeds a given number, switching control 42 is actuated to-discontinue operation of tape deck 10 and initiate operation of tape deck 1]. Tape deck 11 generally records a musical selection with a more complex rhythm component or the like, which is thus selected when the student exceeds a given overall score with the tape deck 10 recorded information. The student is thereby given an automatic and accurately gauged incentive to progress.

The apparatus as hereinbefore described relates primarily to methods and means for ascertaining and improving a students temporal acuity or tempo. However, the same general method and related apparatus are suitable for ascertaining and improving other aspects of the students musical ability besides rhythm. Referring to FIG. 5, apparatus is illustrated for ascertaining a students pitch and providing immediate reinforcement of student performance in the case of correct response. In FIG. 5, tape deck 46 comprises a conventional tape recording and reproducing apparatus, e.g. suitably of the stereo" type, reproducing music on channel A and a reference pitch on channel B. Again, channel B represents sound information which is correlated with the music signal on channel A and represents the desired or accurate student response. The channel A information is amplified by means of amplifier 48 and is supplied to headset 50. A

reference pitch from channel B is amplified by means of an amplifier 52 and is then provided as a first input signal for modulator 54, the latter comprising a mixing or intermodulating circuit for supplying a beat frequency output at 56 comprising the frequency difference of the input signals applied to the modulator. The remaining input to modulator 54 is supplied through amplifier 58 from a microphone 60. If the inputs from amplifiers 52 and 58 to modulator 54 are identical in frequency, then a zero frequency output is present at output lead 56.

The output at 56 is supplied to a detector 62 including a high pass filter followed by rectifying means for providing an output at 64 only when the difference between the signals from amplifiers 52 and 58 exceeds a predetermined frequency value. Indicator 66, suitably comprising a volume unit or decibel meter, will register an output only when the frequency difference exceeds the predetermined amount. An indication is thereby given when the students pitch is incorrect. Alterna-' tively, the output of detector 62 is suitably inverted whereby indication is given by indicator means 66 only in the absence of an output from detector 62. In the latter case an indication is provided as a consequence of the students correct response.

The student wearing headset 50, will play a musical instrument or sing into microphone 60, e.g. employing sheet music. So long as the pitch of the response pro-, vided by the student is close to the reference pitch, the detector 64 will provide no output, assuming a noninverted output thereof is utilized. However, as the students response varies from the reference pitch, appropriate indication will be given. Here again, as in the instance of the devices of FIGS. 1 and 4, the student obtains substantially immediate reinforcement of correct or incorrect response and can, of course, take immediate corrective action in order to improve his performance. Although not shown in FIG. 5, a counting means may be employed to indicate, for example, the number of instances in which the students response was incorrect. Moreover, the reference pitch may be applied to the headset, if desired, when, and for as long as the students response is correct, or the reference pitch may be supplied to the headset in the event the students response is incorrect.

FIG. 6 is a schematic diagram illustrating a portion of the FIG. 1 system in greater detail. In particular, portions of control unit 22 and counter 40 are disclosed in a more detailed manner. It is understood this circuitry is exemplary only and mechanical relays and the like may be replaced with entirely solid state circuitry, if so desired.

Referring to FIG. 6, terminals 68 and 70 are audio signal input terminals for receiving outputs l4 and 16 of amplifier 12 in FIG. 1, while terminal 72 is a common return or ground. Terminal 68 is coupled through resistors 18 and 20 in series to first terminals of headset 24, with resistor 20 being variable for adjusting the volume of the channel A" audio information as heard in the headset. Terminal 70 is coupled by way of the relay contacts 26, switch 74, and resistors 28 and 30 in series to the junction between resistors 18 and 20. In FIG. 6, relay contacts 26 are illustrated as double-throw, and switch 74 is employed to make a selection therebetween. The position of the switch 74 illustrated in FIG. 6 corresponds to the circuit as has been described in connection with FIG. 1, whereby energization of relay coil 32 closes contact 26 and also delivers channel B from terminal headset 24. However, switch 74 may alternatively be thrown to its upper position whereby the channel B" signal will be heard continuously in headset 24 except when the proper response is made by the student. The circuit therefore enables the reverse mode mentioned above. A switch 76 is also provided in series with relay coil 32 for disabling the latter entirely.

The circuitry including battery 36, capacitor 38, and relay coil 32, together with push button 34, operates as a timing circuit in the manner hereinbefore described. The period of time for which relay coil 32 will close contacts 26 for each depression of push button 34 is readily determined by selection of the value of capacitor 38. In a particular embodiment, capacitor 38 had a value of 50 microfarads, the relay comprised a Potter- Brunfield type RSSD, and battery 36 comprised a 24- volt DC source. This combination provides an approximately one-tenth second closure of contacts 26, after which contacts 26 return to the normal position shown.

The remainder of the circuit illustrated in FIG. 6 comprises a portion of counter 40 in FIG. 1. The junction between resistors 28 and 30 is coupled by means of a capacitor 78 to a first terminal of an input resistor 80, the opposite terminal of which is returned to ground terminal 72. Diode 82 is interposed between the first terminal of resistor and a filter capacitor 84, the latter also having its opposite terminal returned to ground. The diode 82, capacitor 84 circuit detects or rectifies such magnetic signals, MS, as are provided via resistor 28 when contacts 26 close, and are detectable.

The junction of capacitor 84 and the cathode of diode 82 is coupled to the base of NPN transistor 86, having its emitter returned to ground andhaving an input resistor 88 disposed between the base thereof and ground. The collector of transistor 86 connects to the positive terminal of supply battery 90 through relay coil 92 and power switch 94. When a signal, MS, is received and rectified by diode 82, transistor 86 amplifies the same and draws current from battery 90 through relay coil 92, closing contacts 94 of the relay. The series combination of resistor 96 and variable resistor 98, connected from the junction of switch 94 and relay coil 92 to the base of transistor 86, comprises an adjustable biasing circuit for transistor 86. Diode 100 disposed across relay coil 92 is employed for absorbing the voltage generated across relay coil 92 by collapse of the field thereof at the end signal MS.

Relay contacts are disposed in series with switch 102, electrically mechanical counter 41, and battery 104. Each time the signal, MS, occurs, relay contacts 95 close and cause electrically operated mechanical counter 41 to increase its indicated numerical output by one digit. This, of course, assumes switch 102 is closed. Mechanical counter 41 thereby provides an accurate indication of the number of correct responses by the student.

If switch 74 is thrown to its upper position, counter 41 will provide an output count indicating all but the correct responses by the student since the signal, MS, will cause actuation of relay coil 92 when the student does not eliminate the same by pushing push button 34 in synchronism with the signal. Thus, in this instance,

a low score will be indicative of a high degree of student ability.

While 1 have shown and described preferred embodiments of my invention, it will be apparent to those skilled in the art that many changes and modifications may be made without departing from my invention in its broader aspects. 1 therefore intend the appended claims to cover all such changes and modifications as fall within'the true spirit and scope of myinvention.

1 claim:

1. Apparatus for ascertaining and improving a students musical ability, comprising:

means for producing a first audio signal with which a student may correlate a related response during the production of said first audio signal,

means for synchronously providing a second audio signal related to a desired correct response from the student, said second audio signal also being systematically related to said first audio signal in synchronized time relation,

means for communicating said first audio signal to said student,

means for receiving a music-related response from said student during the time the student hears said first audio signal,

and means for indicating the correctness of the response by the student in comparison with said second signal including means for communicating said second signal to said student as a result of a correct response by said student, for reinforcement of the students performance, and including means limiting the period of each communication of the second signal'to the student to a predetermined time period substantially initiated by the students response. i

2. Apparatus for improving a students temporal acuity comprising:

audio signal reproducing means for providing a first sound sequence of a nature having a recognizable rhythm, and a second signal'selected to be in time correlation with predetermined elements of said sound sequence,

means for communicating said sound sequence as an output audible to said student,

means for registering a response of said student during the time the student hears said sound sequence,

and means for coupling the said second signal to means for communicating to said student under the control-of said means for registering the students response so that the student hears the second signal only as his response is in time agreement therewith, including timing means intermediate said means for registering a students response and said means for coupling said second signal to said means for communicating to the student, said timing means being operative pursuant to the students response for maintaining said coupling for only a short time period related to the time duration of a said second signal. 3. Apparatus for ascertaining and improving a students musical temporal acuity comprising:

a first source of musical signals containing a rendition of a musical composition; a second source of signals containing a set of signals corresponding to the rhythmic accompaniment to said rendition;

means responsive to said first and second sources for audibly presenting to the student said rendition and said rhythmic accompaniment in their proper timed relationship, said rhythmic accompaniment being presented as discrete beats;

means for blocking the audible presentation of the discrete beats; means actuated by said student for simulating the playing of beats intended to correspond to said rhythmic accompaniment in response to the presentation of said audible rendition;

and means responsive to the said student actuated means for disabling said blocking means for a predetermined and limited time period commencing with the beginning of each of said simulated beats so that said student will hear the respective discrete beat of said rhythmic accompaniment only if said respective discrete beat is time synchronized with said time period thereby giving said student the illusion of playing along with said rendition and giving said student an immediate indication that the timing of said simulated beat is correct.

4. The apparatus according to claim 3 wherein said first and second sources comprise a magnetic tape reproducing apparatus including a magnetic tape having at least two channels upon which said rendition and said set of signals are respectively recorded,

and wherein said means actuated by said student includes switching means for initiating coupling of said set of signals to said means for audibly presenting said rendition and said rhythmic accompanimeans for coupling the said second signal to means for communicating to said student under the control of said means for registering the students response so that the student hears the second signal only as his response is in time agreement therewith,

and timing means operated by said means for registering, for limiting the period of said coupling to a predeterminedtime period.

6. The apparatus according to claim 5 wherein said timing means includes a capacitor discharged in response to operation of said means for registering.

7. The apparatus according to claim 5 further including means for counting the responses of said student in correct time agreement with said second signal.

8. The apparatus according to claim 7 further comprising additional audio signal reproducing means providing a second sound sequence in response to a predetermined total count registered by said means for counting, and means for communicating said second sound sequence as an output audible to said student, in place of said first sound sequence, so thatsaid student may correlate a response therewith.

tape having two channels upon which another first sound sequence and another second signal are respectively recorded,

said another second signal being coupled to said means for communicating to said student under the control of said means for registering the students response, after said predetermined total count is registered. 

1. Apparatus for ascertaining and improving a student''s musical ability, comprising: means for producing a first audio signal with which a student may correlate a related response during the production of said first audio signal, means for synchronously providing a second audio signal related to a desired correct response from the student, said second audio signal also being systematically related to said first audio signal in synchronized time relation, means for communicating said first audio signal to said student, means for receiving a music-related response from said student during the time the student hears said first audio signal, and means for indicating the correctness of the response by the student in comparison with said second signal including means for communicating said second signal to said student as a result of a correct response by said student, for reinforcement of the student''s performance, and including means limiting the period of each communication of the second signal to the student to a predetermined time period substantially initiated by the student''s response.
 2. Apparatus for improving a student''s temporal acuity comprising: audio signal reproducing means for providing a first sound sequence of a nature having a recognizable rhythm, and a second signal selected to be in time correlation with predetermined elements of said sound sequence, means for communicating said sound sequence as an output audible to said student, means for registering a response of said student during the time the student hears said sound sequence, and means for coupling the said second signal tO means for communicating to said student under the control of said means for registering the student''s response so that the student hears the second signal only as his response is in time agreement therewith, including timing means intermediate said means for registering a student''s response and said means for coupling said second signal to said means for communicating to the student, said timing means being operative pursuant to the student''s response for maintaining said coupling for only a short time period related to the time duration of a said second signal.
 3. Apparatus for ascertaining and improving a student''s musical temporal acuity comprising: a first source of musical signals containing a rendition of a musical composition; a second source of signals containing a set of signals corresponding to the rhythmic accompaniment to said rendition; means responsive to said first and second sources for audibly presenting to the student said rendition and said rhythmic accompaniment in their proper timed relationship, said rhythmic accompaniment being presented as discrete beats; means for blocking the audible presentation of the discrete beats; means actuated by said student for simulating the playing of beats intended to correspond to said rhythmic accompaniment in response to the presentation of said audible rendition; and means responsive to the said student actuated means for disabling said blocking means for a predetermined and limited time period commencing with the beginning of each of said simulated beats so that said student will hear the respective discrete beat of said rhythmic accompaniment only if said respective discrete beat is time synchronized with said time period thereby giving said student the illusion of playing along with said rendition and giving said student an immediate indication that the timing of said simulated beat is correct.
 4. The apparatus according to claim 3 wherein said first and second sources comprise a magnetic tape reproducing apparatus including a magnetic tape having at least two channels upon which said rendition and said set of signals are respectively recorded, and wherein said means actuated by said student includes switching means for initiating coupling of said set of signals to said means for audibly presenting said rendition and said rhythmic accompaniment to said student.
 5. Apparatus for improving a student''s temporal acuity comprising: audio signal reproducing means for providing a first sound sequence of a nature having a recognizable rhythm, and a second signal selected to be in time correlation with predetermined elements of said sound sequence, means for communicating said sound sequence as an output audible to said student, means for registering a response of said student during the time the student hears said sound sequence, means for coupling the said second signal to means for communicating to said student under the control of said means for registering the student''s response so that the student hears the second signal only as his response is in time agreement therewith, and timing means operated by said means for registering, for limiting the period of said coupling to a predetermined time period.
 6. The apparatus according to claim 5 wherein said timing means includes a capacitor discharged in response to operation of said means for registering.
 7. The apparatus according to claim 5 further including means for counting the responses of said student in correct time agreement with said second signal.
 8. The apparatus according to claim 7 further comprising additional audio signal reproducing means providing a second sound sequence in response to a predetermined total count registered by said means for counting, and means for communicating said second sound sequence as an output audible to said student, in place of said first sound sequence, so that said student may correlate a response therewith.
 9. The apparatus accordinG to claim 8 wherein said audio signal reproducing means comprises a first magnetic tape recording apparatus for receiving a magnetic tape having two channels upon which said first sound sequence and said second signal are respectively recorded, and wherein said additional audio signal reproducing means comprises a second magnetic tape reproducing apparatus for receiving a second magnetic tape having two channels upon which another first sound sequence and another second signal are respectively recorded, said another second signal being coupled to said means for communicating to said student under the control of said means for registering the student''s response, after said predetermined total count is registered. 